Sajuuk's Main Cannon was a larger version of the Phased Cannon Array mount on the Dreadnaughts. It was the most powerful anti-ship weapon in the Homeworld universe. It was so powerful that only the three Hyperspace cores could deliver enough energy to the cannon to fire, and a whole starship was built to handle it. It could destroy a Battlecruiser with 3 shots, and a destroyer in single shot. With an enormous range of 20000 meters it could strike at any starship far before Sajuuk entered it's sensor range, although this meant Sajuuk needed a spotter ship to fully utilize its range.

This cannon was also the only weapon capable of damaging the planet killers, and could destroy them in five shots.